Once upon a time the technology available to anyone outside of a state government to produce a copy of a document was extremely limited. Pretty much all you could do was make a copy of printed text and, normally, there was no chance that the copy would ever be mistaken for the original document by even by casual observers. As with any technology, time improved the ability to produce very detailed replicas to the point where even multi-colored documents could be reproduced in minute detail by equipment available to the average consumer. Printers interested in maintaining the authentication features of their work began to introduce items to their documents that the copiers of the day couldn’t produce – holograms are one example – but the ever-present measure vs. counter-measure race continued on. Today, features that can’t be copied are harder to produce and more expensive every year.
I my wanderings of the technological news I came across this article on a new application of a biological property found in nature: the manner in which certain butterfly wings take on vibrant, iridescent colors.
… Nanotech Security Corp. in Vancouver is using the natural structure of the wings of a Morpho butterfly, a South American insect famous for its bright, iridescent blue or green wings, to create a visual image that would be practically impossible to counterfeit. The technology was developed at British Columbia’s Simon Fraser University, and licensed to the company.
The phenomenon Nanotech employs is similar to the way some animals, including male peacocks, produce iridescent colors: instead of using proteins and other chemicals to produce a hue, the creature’s feathers or scales play with light, using very tiny holes that reflect different colors or wavelengths. The Morpho does this with complicated scales on its wing that produce shimmering blues and greens.
This process is “tunable,” meaning that you can actually get a very specific color by changing the size of the holes and the distance between them. And because the process uses no inks or other chemicals, it allows you to put a color on something without changing the chemical makeup of the material being colored. In the story, they mention using this as an authentication component on prescription drugs. You could put an identifying logo on a pill that shows it’s genuine without introducing something that someone might react badly to.
A very intriguing technology. I wonder if you apply that to, say, the paint on a car? Perhaps the next Ford Focus would come in an iridescent blue that changes to shimmering green as you pass by. (Of course, I also wonder if the same tech could be used to absorb or scatter, say, radar? Just asking…)